Heat exchanger tank groove geometry

ABSTRACT

A heat exchanger includes a plurality of tubes extending between two tank bodies. At least one tank body includes a crown portion. At least one groove is formed in the crown portion. In order to avoid the creation of a thinner wall section in the crown portion, the inner and outer surfaces that form the groove are offset from each other.

FIELD

The present disclosure relates to tank bodies for heat exchangers. Moreparticularly, the present disclosure relates to the geometry for groovesprovided in the tank body that eliminate any reduction of thickness ofthe tank body.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Heat exchangers are used in automotive vehicles to heat or cool variouscomponents of the vehicle. Heat exchangers typically include a pair offluid tanks, a plurality of tubes, a plurality of fins and a pair ofsupport members. Each of the plurality of tubes extends between the pairof fluid tanks and each of the plurality of tubes defines one or morefluid passages that are in direct communication with a tank cavitydefined by each of the fluid tanks. Each of the plurality of fins isdisposed between adjacent tubes to increase the heat transfer area ofthe heat exchanger. The pair of support members are located on oppositesides of the stacked tubes and fins to provide support for the heatexchanger. Heat is transferred between a fluid flowing in the passagesof the tubes between the fluid tanks and a fluid flowing over the tubesand fins.

The tank bodies that form the fluid tanks can be made from a variety ofmaterials including metals and plastics. The specific material dependson the strength and/or temperature requirements for the heat exchanger.Plastic tank bodies have been utilized when the requirements permit andthese plastic tank bodies reduce weight and costs while still providingthe necessary strength and durability. In order to increase thestiffness of the plastic tank body, grooves are added to the moldedplastic tank body. When the tank body has a uniform cross-section alongits length, these grooves increase the stiffness without reducing thestrength of the plastic tank body.

Some plastic tank bodies are designed with a crown surface which is atan angle with the longitudinal length of the plastic tank body. Thecrown surface is typically used to locate a fluid inlet for addingadditional fluid to the heat exchanger. When a vertical groove is formedin the crown surface of the plastic tank body, the wall thickness of theplastic tank body is reduced at one side of the groove and the wallthickness is increased at the opposite side of the groove due to theintersection of the groove with the crown surface. The reduced wallthickness weakens the plastic tank body. In addition, the increased wallthickness could create molding voids due to the larger volume whichneeds to be filled with plastic during the molding process.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

The present disclosure provides a groove design for a plastic moldedtank body that maintains the same thickness at the intersection of thegroove and crown surface as the thickness of the normal wall of the tankbody. This is accomplished by first keeping the tangent locations of thestart of the inner and outer grooves constant to maintain the normalwall thickness and then offsetting the ends of the inner and outergrooves to provide a thicker wall at the base of the groove whichincreases the wall thickness at the intersection of the groove and thecrown surface.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a front view of a heat exchanger in accordance with thepresent disclosure;

FIG. 2 is a side view of one of the tank bodies of the heat exchangerillustrated in FIG. 1;

FIG. 3 is a top view of the tank body illustrated in FIGS. 1 and 2;

FIG. 4 is a schematic illustrating the relationship between across-section taken in direction A-A in FIG. 2 and a cross-section takenin direction B-B in FIG. 3;

FIG. 5 is a schematic illustrating the relationship between across-section taken in direction C-C in FIG. 2 and a cross-section takenin direction D-D in FIG. 3; and

FIG. 6 is a schematic similar to FIG. 5 but illustrating a prior arttank body.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

Referring to FIG. 1, a heat exchanger 10 is illustrated. Heat exchanger10 comprises an upper tank body 12, a lower tank body 14, a plurality oftubes 16, a plurality of fins 18 and a pair of support members 20.

Each of the plurality of tubes 16 extend between upper tank body 12 andlower tank body 14. Each of the plurality of tubes 16 define one or morefluid passages that carry a working fluid between a chamber defined byupper tank body 12 and a chamber defined by lower tank body 14. Each ofthe plurality of fins 18 is disposed between adjacent tubes 16 and arebonded or brazed to the adjacent tubes 16. The plurality of fins 18increase the area of the heat exchanger surface of heat exchanger 10 inorder to increase the capacity and performance of heat exchanger 10. Thepair of support members 20 are located at opposite sides of the stack oftubes 16 and fins 18 to increase the strength of the stacked components.

Referring to FIGS. 1-3, upper tank body 12 includes a filling port 30, afluid inlet 32 and a plurality of grooves 34. The plurality of grooves34 provide additional stiffness and support for upper tank body 12.Upper tank body 12 defines a crowned portion 38 at the center of uppertank body 12 where filling port 30 is located. The crowned portion 38 isdefined by a pair of walls 40 that are angled upwards as illustrated inFIG. 1. On each side of crowned portion 38, upper tank body 12 defines astraight portion 42. Lower tank body 14 includes a fluid outlet 46 and aplurality of grooves 48. The plurality of grooves 48 provide additionalstiffness and support for lower tank body 14. As an example, if heatexchanger 10 is a radiator for cooling an engine of a vehicle, thecooling system for the vehicle including heat exchanger 10 is filledwith engine coolant through filling port 30. As the engine operates, anengine coolant pump pumps engine coolant through the engine. The enginecoolant leaves the engine and is pumped to fluid inlet 32 of upper tankbody 12. The engine coolant flows through upper tank body 12, throughthe plurality of tubes 16 and into lower tank body 14. From lower tankbody 14, the engine coolant is supplied to the pump through fluid outlet46. As the engine coolant flows through the plurality of tubes 16, itexchanges heat with air blown over the plurality of tubes 16 and theplurality of fins 18.

Referring now to FIG. 4, a comparison of a cross-section of groove 34taken in direction AA in FIG. 2 and a cross-section taken in directionB-B in FIG. 3 is illustrated. In FIG. 4, groove 34 is located in one ofstraight portions 42 of upper tank body 12. As illustrated in FIG. 4,groove 34 has an outer surface starting point 50, an outer surfaceending point 52, an inner surface starting point 54 and an inner surfaceending point 56. Inner surface starting point 54 is shifted from outersurface starting point 50 by a specified amount and inner surface endingpoint 56 is shifted from outer surface ending point 52 by the samespecified amount in order to maintain the thickness of material throughgroove 34 the same as the thickness of material in non-grooved portionof upper tank body 12. The offset is the same between sections A-A andB-B because the two surfaces where these sections were taken areparallel, both being perpendicular to groove 34.

Referring now to FIG. 5, a comparison of a cross-section of groove 34taken in direction C-C in FIG. 2 and a cross-section taken in directionD-D in FIG. 3 is illustrated. In FIG. 5, groove 34 is located in crownedportion 38 of upper tank body 12. As illustrated in FIG. 5, groove 34has an outer surface starting point 60, an outer surface ending point62, an inner surface starting point 64 and an inner surface ending point66. Inner surface starting point 64 is shifted from outer surfacestarting point 60 by a first specified amount and inner surface endingpoint 66 is shifted from outer surface ending point 62 by a secondspecified distance where the second specified distance is different thanthe first specified distance. This difference has the effect ofoffsetting the inner surface and outer surface of groove 34 in order tokeep the thickness of material in groove 34 the same or greater than thethickness of material in non-grooved portion of crowned portion 38 ofupper tank body 12 and thus avoid weakening upper tank body 12.

Inner surface starting point 64 is shifted from outer surface startingpoint 60 by the first specified distance and the first specifieddistance is determined such that the thickness A of material through thebent section after outer and inner surface starting points 60 and 64 insection C-C is maintained the same as the thickness A of material in thenon-grooved portion of upper tank body 12. As illustrated in FIG. 5, dueto the inclined surfaces of crowned portion 38, the thickness B ofmaterial in section D-D at the bent section after outer and innersurface starting points 60 and 64 of groove 34 is increased in crownedportion 38 as compared to thickness A in section C-C.

Inner surface ending point 66 is shifted from outer surface ending point62 by the second specified distance and the second specified distance isdetermined such that the thickness A of material through the bentsection before outer and inner surface ending points 62 and 66 insection D-D are maintained the same as the thickness A of material inthe non-grooved portion of upper tank body 12. As illustrated in FIG. 5,due to the inclined surfaces of crowned portion 38, the thickness D ofmaterial in section C-C through the bent section before outer and innersurface ending points 62 and 66 of groove 34 is increased in crownedportion 38 as compared to section D-D. This has the effect of offsettingthe inner surface of groove 34 with respect to the outer surface ofgroove 34.

FIG. 6 illustrates the prior art designs where the inner and outersurfaces of groove 34 are not offset as in the present invention. InFIG. 6, section C-C has both the thickness A through the bent sectionbefore outer and inner surface starting points 60 and 64 and through thebent section before outer and inner surface ending points 62 and 66.These thicknesses A are maintained the same as the thickness A ofmaterial in a non-grooved portion of upper tank body 12. Due to theinclined surface of crowned portion 38, the thickness B of material insection D-D through the bent section after surface starting points 60and 64 of groove 34 is increased in crowned portion 38 as compared tothickness A in section C-C. Due to the inclined surface of crownedportion 38, the thickness C of material in section D-D through the bentsection before surface ending points 62 and 66 of groove 34 is decreasedin crowned portion 38 as compared to thickness A in section C-C. Thisdecreased thickness represents a weakened area of upper tank body 12.This weakened area is eliminated by the offsetting of the inner surfacewith respect to the outer surface of groove 34.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

What is claimed is:
 1. A heat exchanger comprising: a plurality oftubes, each tube defining at least one fluid passage; a first tank bodydisposed at a first end of said plurality of tubes, each of the at leastone fluid passages being in fluid communication with a chamber definedby the first tank body; a second tank body disposed at a second end ofsaid plurality of tubes, each of the at least one fluid passages beingin fluid communication with a chamber defined by the second tank body,the second tank body comprising: a crown portion defined by a pair ofangled walls; and at least one groove formed into the crown portion;wherein a wall thickness of the tank body in the entire groove is equalto or larger than a wall thickness of the tank body outside the groove.2. The heat exchanger according to claim 1, wherein the groove includesan outer surface starting point, an outer surface ending point, an innersurface starting point and an inner surface ending point, the innersurface starting point being shifted from the outer surface startingpoint by a first amount, the inner surface ending point being shiftedfrom the outer surface starting point by a second amount, the secondamount being greater than the first amount.
 3. The heat exchangeraccording to claim 2, wherein the groove defines a first bent portionafter the outer and inner surface starting points and a second bentportion before the outer and inner surface ending points.
 4. The heatexchanger according to claim 3, wherein a first portion of the firstbent portion has a wall thickness less than a wall thickness of a secondportion of the first bent portion.
 5. The heat exchanger according toclaim 4, wherein a first portion of the second bent portion has a wallthickness greater than a wall thickness of a second portion of thesecond bent portion.
 6. The heat exchanger according to claim 3, whereina first portion of the second bent portion has a wall thickness greaterthan a wall thickness of a second portion of the second bent portion. 7.The heat exchanger according to claim 1, wherein the groove defines afirst bent portion at a first side of the groove and a second bentportion at a second side of the groove.
 8. The heat exchanger accordingto claim 7, wherein a first portion of the first bent portion has a wallthickness less than a wall thickness of a second portion of the firstbent portion.
 9. The heat exchanger according to claim 8, wherein afirst portion of the second bent portion has a wall thickness greaterthan a wall thickness of a second portion of the second bent portion.10. The heat exchanger according to claim 7, wherein a first portion ofthe second bent portion has a wall thickness greater than a wallthickness of a second portion of the second bent portion.
 11. The heatexchanger according to claim 1, wherein the tank body defines a straightportion at both sides of the crown portion.
 12. The heat exchangeraccording to claim 11, wherein the groove includes an outer surfacestarting point, an outer surface ending point, an inner surface startingpoint and an inner surface ending point, the inner surface startingpoint being shifted from the outer surface starting point by a firstamount, the inner surface ending point being shifted from the outersurface starting point by a second amount, the second amount beinggreater than the first amount.
 13. The heat exchanger according to claim12, wherein the groove defines a first bent portion after the outer andinner surface starting points and a second bent portion before the outerand inner surface ending points.
 14. The heat exchanger according toclaim 13, wherein a first portion of the first bent portion has a wallthickness less than a wall thickness of a second portion of the firstbent portion.
 15. The heat exchanger according to claim 14, wherein afirst portion of the second bent portion has a wall thickness greaterthan a wall thickness of a second portion of the second bent portion.16. The heat exchanger according to claim 13, wherein a first portion ofthe second bent portion has a wall thickness greater than a wallthickness of a second portion of the second bent portion.
 17. The heatexchanger according to claim 11, wherein the groove defines a first bentportion at a first side of the groove and a second bent portion at asecond side of the groove.
 18. The heat exchanger according to claim 17,wherein a first portion of the first bent portion has a wall thicknessless than a wall thickness of a second portion of the first bentportion.
 19. The heat exchanger according to claim 18, wherein a firstportion of the second bent portion has a wall thickness greater than awall thickness of a second portion of the second bent portion.
 20. Theheat exchanger according to claim 17, wherein a first portion of thesecond bent portion has a wall thickness greater than a wall thicknessof a second portion of the second bent portion.